This invention relates to an apparatus and method for envelope flap opening, also known as envelope flapping.
Envelopes commonly have a body and a flap which is sealed to the body when the required contents have been inserted into the body. The envelopes are conventionally supplied with the flaps folded onto but not sealed to the body and, thus, before any contents can be inserted the flap must be opened from its initial closed state. In the case of inserter systems, such as used by organisations, banks for example, for large volume mailings, the flap opening is required to be achieved in an automated manner. Numerous flap opening means have previously been proposed. For example, in U.S. Pat. No. 2,668,053 and U.S. Pat. No. 2,766,569, both assigned to Pitney Bowes Inc., the Applicant, envelopes are fed into a flapping mechanism with the flap closed and at the leading edge of the fed envelope, and flapped (the flap opened) as the envelope is reversed out of the flapping mechanism and driven to the next processing station, with the body at the leading edge.
The present invention aims to provide a method and means for unflapping envelopes which is low cost and thus particularly appropriate for lower volume applications, such as SOHO (small office/home office) applications.
According to one aspect of the present invention there is provided a method of flapping an unflapped envelope having a body and a flap and a crease line therebetween, including the steps of: feeding the unflapped envelope in a first direction along a first path with the crease line trailing; performing a first reversal of the feed direction and feeding the unflapped envelope with the crease line leading, along a flapper path adjoining the first path and opening into a flapping zone, until the flap is engageable by flapper blade means; and performing a second reversal of the feed direction and feeding the envelope back along the flapper path, the second reversal and feeding causing the flap to be engaged by the flapper blade means and stripped from the body of the envelope.
According to another aspect of the present invention there is provided apparatus for flapping an unflapped envelope having a body and a flap and a crease line therebetween, including: reversible drive means for feeding the envelope; a first path; a flapper path adjoining the first path and leading to a flapping zone; flapper blade means associated with the flapping zone; and control means serving to control the drive means such that in use of the apparatus an unflapped envelope is fed in a first direction along the first path with the crease line leading; such that when the crease line reaches a predetermined position along the first path the drive means is reversed and the envelope driven along the flapper path with the crease line leading at least until the flap is engageable by the flapper blade means; and such that the drive means is then reversed again whereby the envelope is driven back along the flapper path and stripping of the flap from the body of the envelope is achieved by the flapper blade means.
The method and apparatus is such that the envelope is flapped by reversing up a separate path and then driving forward again, when the forward motion of the envelope serves to strip the flap away from the body of the envelope, as a result of contact with the flapper blade means. Such an arrangement minimizes the number of moving parts required and thus minimizes the cost.
Preferably the envelope feeding, once it has been delivered from an envelope feeder, is achieved by a roller pair disposed downstream of the junction between the flapper (separate) path and the first path.
The edges of the flap, as it enters the flapper zone, may be deflected by deflector means, in order to initiate flap opening.
Sensor means may be included to sense when the flap has reached the predetermined position along the first path, and cause subsequent reversal of the drive means, and/or to sense when the flap is sufficiently within the flapping zone for stripping and to cause subsequent reversal of the drive means. The deflector means may provide the latter sensing function.
In the case of flapper blade means comprised of at least one pair of elements spaced across the width of the flapper path and having flap opening surfaces on which the envelope flap can ride, the distance the envelope needs to be driven into the flapping zone can be reduced in comparison with use of a full width flapper blade, particularly for long triangular flap styles. Thus minimizing space requirements.